If the woman isn't defiled, but is clean, then she shall be free and shall conceive seed.
The Ohr Hachaim notices that the possuk seems to be repeating itself, as the woman was not only ‘not defiled,’ but she is also ‘clean’. Why does the Torah seemingly repeat itself?
The Ohr Hachaim explains that the woman who was not defiled is not just free of the punishment of the wayward wife. The Torah also promises that this woman will be amply rewarded for being unjustly suspected. She will have children and successful, good-looking, wise children at that. However, for this she needs to be more than ‘not defiled.’ Not only must she have kept herself far from any adultery with a strange man, but she must also have kept herself pure. She must also have acted with total chastity, not having even touched a strange man. If she acted with this level of modesty, she would be rewarded with children. However, if she did not act modestly, even if she never actually sinned with another man, she would not receive this blessing that the Torah promises for the woman who remained pure.
The Ohr Hachaim proves his position from another possuk. The Torah says וְּהִשְּׁבִיעַ אֹתָהּ הַכֹהֵן וְּאָמַר אֶל הָאִשָה אִם לֹא שָׁכַב אִישׁ אֹתָךְ וְּאִם לֹא שָׂטִית טֻמְּאָה תַחַת אִישֵׁךְ הִנָקִי מִמֵי הַמָרִ ים הַמְּאָרֲרִ ים הָאֵלֶה - The Cohen shall cause her to swear and shall tell the woman, 'If no man has lain with you, and if you haven't strayed to uncleanness, being under your husband, be free from this water of bitterness that brings a curse.' The Cohen has her make two oaths – if no man has lain with her, and if she hasn’t strayed. This refers to the two kinds of possible strayings; she could either have fornicated with a strange man, or she could have acted inappropriately without having actually committed adultery. She is only completely clean if she has acted with full propriety.
